Varietal forms of Spondylus spinosus Schreibers, 1793, an Indo-Pacific spondylid are figured and described. Spondylus cf multisetosus Reeve, 1856, previously only known from the Indo-Pacific Ocean, is recorded from the Iskenderun region for the first time, figured, and discussed. Other species of Chamidae and Ostreidae, which live commensally and on the Spondylus species, are also discussed.